Fast Marina Magazine

I am about to start rebuilding the B series enine for my Marina based Marlin. It's done 130k miles so I am expecting a fairly major rebuild.
So far on my shopping list is:

1. Peter Burgess Econotune head (I need an unleaded head conversion anyway)
2. +60 rebore. (After 130k it will undoubtedly need a rebore and it seems rude not to go up to the maximum to get that little bit extra torque!)

The car was originally an SC which I believe has a softer camshaft than the TC, and anyway I guess the camshaft will be pretty worn, so I am expecting to have to replace it. The question is with what? There are many options available it seems - most of which are probably unsuitable for a road car. And would I also need to change the distributor for one with a different advance curve? It's probably also worn out so it would be money well spent...

Cheers, Robin

Ha ha, been there and done all that exactly.

I found that the following combination worked really well.

Peter Burgess Econotune unleaded head
Twin HS4 SUs with AAA needles
MGB cast iron exhaust manifold (unless you can find the Marina TC equivalent)
Early MGB distributor
Piper 270 camshaft and new followers
Electric fuel pump
Electric radiator fan

The Econotune head worked OK with the standard camshaft single HS6 carb with a different needle and standard distributor.

You can read about it on my car’s website www.marinacoupe.co.uk

The Piper 270 camshaft didn’t really come alive until I fitted the twin HS4 SUs and the MGB distributor.

Don’t bother with twin HS6s as the engine will be over-carbed (and expensive).

Thanks Chris
Fortunaletly I have the TC manifold as the previous owner had fitted some twin carbs without doing much else.
Piper 270 camshaft now seems to be a rare beast, at least at a price that is nice, but I have found the cam timings and can probably find something equivalent.
May I ask - what is an early MGB distributor? Does it have a particular part number and/or features?

Cheers, Robin

All distributors have slightly different maximum advance and return springs, developed specifically for particular engine/car options. The Peter Burgess book on B series tuning specifically recommended the early MGB distributor as the best option on the engine. The early MGB unit is 12H3580, it retains the vacuum advance and micrometer advance/retard adjustment.

Piper themselves offer reprofiled BP270 cams on exchange here https://www.pipercams.co.uk/product/bbp270r

The Marina dizzies were slanted more towards economy on part throttle opening (cruising), rather than out and out performance.

I've got a 285 cam in mine and a Burgess fast road head (standard fast road version with the larger factory inlet valve) on an 1860. That's the combination I was recommended by the engine builder (and I was a bit swayed by being too conservative with the cam for my big 6 Triumph) - I think it's going to be a bit too far the other way to be honest and I should have gone with the 270. I haven't driven it yet...

An alternative all be it slightly lower powered camshaft than the Piper 270 camshaft (or the Piper 255 camshaft) is the standard MGB and Marina TC camshaft which is definitely more powerful than the Marina Super camshaft. Here’s one for sale on eBay https://www.ebay.co.uk/itm/381518146536

The part number is 88G303.

Mine has a ‘boring’ 255 cam which I’ll probably change one day.
The 40% increase in torque is probably mostly due to the capacity increase but the cam certainly helps in making a great ‘real world’ engine. Lots of low and mid range torque, just lacking a little above 4k rpm.

Plenty of recipes and considerations in Peter's book...well worth reading in detail.
I've got a +60 block with an big-valve head (originally from MGB 72-74 I think), standard TC/MGB cam, TC inlet manifold and twin HS4 (AAA needles) plus an Aldon dizzy (with the correct curve for the manifold vacuum take-off) plus MGA exhaust manifold (3-1, so easier to bodge!)...it all works really nicely together. Not outrageously powerful but well-suited to the lightweight Roadster.

OK - thanks to everyone for their input. I have read the Peter Burgess book cover to cover - the only problem is too many options!
My current favourite is the 270 cam which it seems you can get direct from Piper as an exchange for a reasonable price.
Of course I may change my mind by the time I actually come to do it lol.

Cheers, Robin